This invention relates primarily to technology for enhancing the interface of an intelligent mobile telephone, a smart phone, a personal digital assistant (PDA) or like device having a display, a processor and a mobile operating system with a graphical interface. An example is the Microsoft Windows Mobile operating system used in cellular telephones and PDAs having a processing unit capable of supporting the operating system. Smart phones herein encompass hand-held small mobile computers with some telecommunication capability and that are functional as telephones and that have primary constraints on size, weight and portability. Such constraints, as a consequence, impose constraints on power, display resolution and data entry capabilities, as compared with portable laptop computers, desktop computers and the like. For the purposes of this invention, there is no distinction to be drawn between smart phones and handheld personal digital assistants, so hereinafter the terms may be used interchangeably.
Smart phones are becoming a primary personal data assistant, since they can provide a host of functions integrated into a single pocket-sized computer unit, including telephone, email, messaging, internet access, calendar, calculator, task managers, word processor, still and video camera, clock and alarm clock, as well as a an audio and video entertainment center, game console, GPS, and a host of other computer-based functions. A smart phone can even serve as a flashlight. However, the major strength of the smart phone—its extreme portability—is also a major weakness. Because of its inherent small size, the smart phone is not able to provide a display or a fully functional keyboard and pointing device useable for office applications such as word processing, spreadsheet programs, email clients, etc. These constraints limit the potential versatility of the smart phone.
A class of hardware and software products exist to address the so-called KVM (keyboard-video-mouse) interface problem. Unlike a conventional KVM application wherein a fixed asset is made accessible at a remote location, this invention relates to enhancing limited capabilities of a typical mobile asset in a local environment. Extended keyboards have been developed for selected personal digital assistants (PDAs). Software has been developed to extract data from smart phones for use on the mobile or desktop computers. Hot sync capability provides backup but does not necessarily provide a complete mirror of the content of mobile device. Screen copier programs copy phone display images to desktop computer screens, but do not enhance phone display resolution.
The challenge is to provide enhanced display output to a high resolution display device, such as a projector or a desktop display, over a limited bandwidth in a reasonable refresh rate. One known technique is the so-called screen scraping technique. According to this technique, an application is installed that gains access to the primary display driver display buffer and periodically copies its content to a network protocol for remote viewing. In another method, the default primary display driver is replaced with another display driver that typically has a higher resolution. These techniques are noticeably slow to execute, since they must copy post-rendered data via the operating system to an add-on application. Another disadvantage is that periodic sampling may result in missing content. This process is inefficient and can leave an unsatisfactory visual impression and noticeably slow display of images, particularly video images.
What is needed is a technique to provide an alternative video display for handheld smartphones or PDAs.